Photophoretic velocities of dust aggregates of various radii (labeled curves with radii given in metres) in the midplane of a transparent minimum mass solar nebula as given by Eq. (4). Panels a) to d) show the results for heat conductivities of the dust aggregates of λ_p = 10^-3   W   m^-1   K^-1, λ_p = 10^-2   W   m^-1   K^-1, λ_p = 10^-1   W   m^-1   K^-1, and λ_p = 1   W   m^-1   K^-1, respectively. The luminosity of the central star is assumed to be equal to the solar luminosity, and J₁ = −0.5.